body {
  margin: 0;
  padding: 0;
}

section {
  height: 25vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.s1 {
  background: #3498db;
}

.s2 {
  background: #e74c3c;
}

.s3 {
  background: #2ecc71;
}

.s4 {
  background: #34495e;
}

.iconbtn {
  width: 80px;
  height: 80px;
  text-decoration: none;
  margin: 20px;
  position: relative;
  font-size: 30px;
  border-radius: 50%;
}

.iconbtn::before {
  position: absolute;
  z-index: 1;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}

.iconbtn::after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  border-radius: 50%;
  z-index: 0;
}

.s1 .iconbtn,
.s2 .iconbtn {
  color: #fff;
}

.s1 .iconbtn::after {
  border: 4px dashed;
}

.s1 .iconbtn:hover::after {
  animation: ro 7s linear infinite;
}

.s2 .iconbtn {
  border: 4px solid;
}

.s2 .iconbtn:hover {
  animation: ro 2s linear infinite;
}

.s3 .iconbtn {
  border: 4px solid #fff;
  color: #2ecc71;
}

.s3 .iconbtn::after {
  background: #ffffff;
  transition: .2s;
}

.s3 .iconbtn:hover::after {
  transform: scale(.9);
}

.s4 .iconbtn {
  border: 4px solid #fff;
  color: #34495e;
}

.s4 .iconbtn::after {
  background: #fff;
  transition: .4s;
}

.s4 .iconbtn:hover::after {
  transform: scale(1.3);
  opacity: 0;
}

.s4 .iconbtn:hover {
  color: #fff;
}

@keyframes ro {
  0% {
    transform: rotate(0);
  }

  100% {
    transform: rotate(360deg);
  }
}